Not only is the Typhon Pact full of races that seem to oddly matched...just look at the "Khitomer Pact".
-The Federation and the Klingons have been allies for the better part of a century, except for that little war in 2372.
-The Imperial Romulan State, when they were part of the Romulan Star Empire, has been at war with both the Federation and the Klingons before. Long standing grudges still exist.
-The Federation/Klingon/Romulan alliance fought against the Cardassians when they were a part of the Dominion.
-The Federation and the Ferengi were also hostile towards each other, although not always openly (Maxia Zeta in 2355), in the 2360's.
Romulans think everyone else is inferior compared to themselves, and so did the Cardassians, for quite some time. It will be interesting to see if the new "Khitomer Pact" is better at working together than the Typhon Pact. Remember...the Typhon Pact formed first, while the "Khitomer Pact" was formed as a response. Maybe the Khitomer nations aren't as prepared to work together as the Typhon nations are...
That's getting ahead of things. There is no "Khitomer Pact" at the moment. The last book to mention that only said certain nations had been invited to attend a summit to discuss possible expansion of the Accords, and not even all of those nations had responded to that invitation at that point.